1. Technical Field
The disclosure relates to an optical device and, more particularly, to a reflector and an LED (light emitting diode) light-emitting unit employing the reflector.
2. Description of Related Art
Generally, a most commonly used light-emitting unit includes a light-emitting element and a reflector mounted around the light-emitting element for reflecting light emitted from the light-emitting element. The reflector includes a light-reflecting unit surrounding the light-emitting element. The light-reflecting unit has a hemispheric face converging the light emitted from the light-emitting element within a substantially round region. When the light-emitting unit is utilized in a road illumination, there are identical illumination regions in a longitudinal direction of the road and in a lateral direction of the road. In order to achieve a desired illumination which has a wider illumination region along the longitudinal direction of the road and a narrower illumination region along the lateral direction of the road, the reflector needs to be amended.
What is needed, therefore, is a reflector capable of guiding light emitted from a light-emitting element to be in a wider illumination region along the longitudinal direction of the road and a narrower illumination region along the lateral direction of the road and a light-emitting unit using the reflector.